A connection structure which electrically connects a connection terminal of an antenna element mounted on a mounting plate to a connection terminal of a coaxial cable connector mounted on the mounting plate, includes a plate-shaped electric connection member which includes an element connection end part electrically connected to the connection terminal of the antenna element and a cable connector connection end part extending away from the element connection end part and having a tapered shape. The connection structure further includes a bar-shaped electric connection member which extends along the cable connector connection end part of the plate-shaped electric connection member and which is electrically connected to the cable connector connection end part. Both the cable connector connection end part of the plate-shaped electric connection member and the bar-shaped electric connection member are electrically connected to the connection terminal of the coaxial cable connector.